Epinephrine(adrenaline) is a catechol neurotransmitter and hormone widely used in the preparation of drugs such as cardiac resuscitation, bronchiectasis, anaphylaxis and urokinase. In clinical application, conventional preparation methods mainly include biological methods, chemical methods and biosynthetic methods. This article will analyze these preparation methods.
1. Biological method:
The biosynthesis of adrenaline usually uses tyrosine as a precursor, which is produced through multiple enzyme-catalyzed reactions. The synthesis and catalysis of these enzymes are regulated by various factors, such as hormones, neurotransmitters and drugs.
1) Conversion of tyrosine hydroxylase into DOPA:
The first compounds to be synthesized were phenolic carboxylic acids.
Phenolic carboxylic acid is converted to 3,4-dihydroxyphenylalanine (DOPA) by tyrosine hydroxylase. This response is regulated by the hormone dopamine and its derivatives, neurotransmitters or neuropharmaceuticals.
2) DOPA is oxidized to generate dopamine:
DOPA decarboxylase also oxidizes DOPA to dopamine by an enzyme mediated by the synthesis of dopamine.
3) N-methyltransferase prompts dopamine to generate norepinephrine:
Norepinephrine is converted to epinephrine by the action of dopamine N-methyltransferase.
Techniques commonly used in biological methods include protein engineering and gene engineering.
2. Chemical method:
In chemical synthesis, tyrosine and formaldehyde form methyl-DOPA (Maxwell's reagent) through 1,4-addition reaction. Methyl-DOPA decomposes at 60 °C by Decarboxylation to form adrenalin.
Chemical synthesis of epinephrine mainly includes the following reactions:
1) Michael addition of tyrosine and formaldehyde
Tyrosine and formaldehyde undergo 1,4-Michael addition reaction under suitable reaction conditions to generate methyl-DOPA intermediate.
2) Decarboxylation
The methyl-DOPA intermediate decomposes at high temperature through the Decarboxylation reaction to form epinephrine.
The advantages of chemical synthesis of adrenaline include not being bound by biocatalysis, high synthesis efficiency, and the ability to prepare a variety of adrenaline derivatives through structural changes. However, the chemical method also has disadvantages such as complicated process and high cost.
3. Biosynthesis:
Biosynthetic synthesis of adrenaline is mainly carried out using microbial synthesis technology. By screening and modifying microbial strains, they can produce adrenaline.
Common production host microbial strains for gene recombination include Escherichia coli, Saccharomyces cerevisiae, Trichoderma, etc., and the synthesis of epinephrine by recombinant expression of Escherichia coli is a more popular way. The core of the method is to take the metabolic pathway of tyrosine out of the cell, and then cultivate its metabolic pathway in the container, so that it can produce a large amount of adrenaline. Most of this approach is automated and easily scalable.
4 Conclusion:
Biological methods, chemical methods and biosynthetic methods are all conventional methods for the preparation of epinephrine. The biological method can truly generate natural adrenaline from the perspective of physiology and pharmacology, and can obtain natural drug effects, but it is regulated by genes and enzymes, making it difficult to prepare; chemical and biosynthetic methods have high efficiency and high yield. , Highly characterization and modification characteristics, but the chemical process is cumbersome and costly, and the biosynthesis method is difficult to maintain efficiency but can effectively coordinate microbial growth and metabolism for mass production.
Epinephrine (epinephrine), a neurotransmitter and hormone, is also an important drug. It produces physiological effects by binding to adrenergic receptors. Epinephrine includes amphetamine and catecholamine derivatives and is commonly used to treat conditions such as asthma, fast heartbeat and severe allergic reactions. In addition, the drug is also used in the process of first aid and assisted delivery.
The chemical reaction of Epinephrine involves the interaction of multiple chemical parts, so this article will introduce the role of these parts in the chemical reaction.
Chemical structure:
First, the chemical structure of Epinephrine is introduced. Epinephrine molecule is composed of phenylethylamine structure and catechol ring structure, the abbreviation is Epi. There are two chiral carbon atoms, located in the α and β positions, respectively. Therefore, Epinephrine exists in four stereoisomers, namely (R,R)-Epi, (S,S)-Epi, (R,S)-Epi, (S,R)-Epi. Among them, only (R,R)-Epi is the isomer with strong physiological activity, which is also the main isomer produced in vivo.
Reaction of Epinephrine with Hydrogen Ions:
There are hydroxyl and amine groups on the benzene ring of Epinephrine, so it has a certain acidity and alkalinity. When Epinephrine interacts with hydrogen ions (H^+), the following reactions can occur:
Epi + H^+ → EpiH^+
This is a critical reaction because EpiH^+ is a product of the ionization of Epinephrine, thereby affecting its properties in physiological and pharmacological effects.
Oxidation reactions of Epinephrine:
The hydroxyl and amphetamine groups of Epinephrine have obvious redox properties and can undergo oxidation reactions. When Epinephrine comes into contact with oxygen, the following reactions can occur:
Epi + O2 → EpiO2
In addition, when Epinephrine comes into contact with certain oxidizing agents such as hydrogen peroxide, an oxidation reaction can also occur.
Acid-base reaction of Epinephrine:
The hydroxyl and amine groups of Epinephrine are also acidic and basic, and they can produce complex acid-base reactions at different pH values. When the pH value is lower than the pKa value of the compound (3.5 and 9.0), then, the hydroxyl group will be protonated, resulting in a strong Lewis acid EpiH^+; conversely, when the pH value is higher than the pKa, the amine group will be deprotonated, Epi^- yields a strong Lewis base. This interplay of acidic properties and pH has a significant impact on the efficacy and side effects of Epinephrine in medical applications.
Nitrogen gasification reaction of Epinephrine:
The amine group in Epinephrine can also undergo nitrogenation reaction when exposed to certain chemical reagents due to redox properties. For example, when Epinephrine comes into contact with mercury nitrate, it produces a dark blue chemical reaction:
Epi + Hg(NO3)2 → HgO2N-Epi + 2HNO3
The above are several typical types of Epinephrine chemical reactions, and each part of it plays different roles in the reaction. The characteristics and properties of chemical reactions have an important impact on the pharmacological effects and medical applications of Epinephrine, and also provide guidance and ideas for chemists and pharmacologists to develop better drugs.